1. Technical Field
Embodiments of the present disclosure relate to an air conditioner.
2. Description of the Related Art
Typically, in an air conditioner including an outdoor unit and an indoor unit that are connected to each other via a liquid pipe and a gas pipe, an opening degree of an expansion valve is controlled so that a refrigerant subcooling degree or a refrigerant superheating degree in a refrigerant exit opening of an indoor heat exchanger of the indoor unit reaches a predetermined target value. For example, an air conditioner described in JP-A-2011-007482 includes an outdoor unit and an indoor unit. The outdoor unit includes a compressor, a four-way valve, and an outdoor heat exchanger. The indoor unit includes an indoor heat exchanger and an indoor expansion valve. For example, during a heating operation, connection of the four-way valve is changed so that a refrigerant is recirculated through the compressor, the indoor heat exchanger, the indoor expansion valve, and the outdoor heat exchanger, in this order. Consequently, the outdoor heat exchanger serves as an evaporator, and the indoor heat exchanger serves as a condenser. Then, the opening degree of the indoor expansion valve is controlled so that the refrigerant subcooling degree in the refrigerant exit opening of the indoor heat exchanger reaches a target value, thereby allowing the indoor unit to exert a necessary heating capacity.
Incidentally, in the air conditioner described in JP-A-2011-007482, one outdoor unit is connected to one indoor unit via a refrigerant pipe. Also in an air conditioner in which one outdoor unit is connected to a plurality of indoor units via a refrigerant pipe, opening degrees of indoor expansion valves of the respective indoor units are controlled so that refrigerant subcooling degrees or refrigerant superheating degrees of the indoor units reach a target value.